1. Field of the Invention
The present invention relates to a cleaning liquid, and an anticorrosive agent for copper or a copper-containing metal.
2. Related Art
Semiconductor devices are formed by laminating a metal wiring layer, a low dielectric layer, an insulating layer or the like on a substrate such as a silicon wafer, and such semiconductor devices are manufactured via processing of each of these layers by a lithography method including carrying out an etching treatment using a resist pattern as a mask.
Residual matter derived from a resist film and a temporarily laminated film (may be also referred to as “sacrificial film”) used in the lithography method, as well as the metal wiring layer and the low dielectric layer generated in an etching step are eliminated using a cleaning liquid so as not to be a hindrance for the semiconductor device, and not to obstruct the following step(s).
Furthermore, in recent years, methods of forming wiring have been adopted in which a damascene method is used, in accordance with increased density and enhanced integration of semiconductor devices. According to such a method of forming wiring, copper, a copper-containing metal or the like that is susceptible to corrosion is employed as a metal wiring material that constitutes a metal wiring layer of a semiconductor device.
In the manufacturing methods of these semiconductor devices, an alkaline, acidic or neutral cleaning liquid is used according to the type of the residual matter to be eliminated, whereby corrosion of copper and copper-containing metals is a problem that results from the cleaning liquid. The problem of corrosion of the copper and copper-containing metals is remarkable in the case in which an acidic or alkaline cleaning liquid is used. Therefore, development of a cleaning liquid that prevents these copper and copper-containing metals, etc., from corrosion when cleaning a substrate has been demanded.
In order to solve the problem of corrosion of copper and copper-containing metals, etc., resulting from such a cleaning liquid, a cleaning liquid was proposed which contains as an anticorrosive agent, for example, an alcohol having no less than 2 carbon atoms in which at least one mercapto group is included in the molecule, and a mercapto group and a hydroxyl group are bound to adjacent carbon atoms (see Patent Document 1).    [Patent Document 1] Japanese Unexamined Patent Application, Publication No. 2000-273663